Currently the bus operation is much the same as it was three years ago with 20 minute scheduled headways to most resorts, 30 minutes to a few, with additional service in mornings and evenings.
The official Bus On Demand system was to have machines similar to fastpass machines that you swipe your room key through to request a bus. This has not been done yet but for many years numerous experiments in bus scheduling have gone on. The closest thing to Bus On Demand has been cast members with walkie talkies at bus stops at various times calling for additional buses as needed.
The proverbial 45 minute wait for a bus that comes too full and you ahve to wait for yet the next one still happens. The transit industry has a term, "missed trip" to describe this. Bus On Demand, and also the current manual scheduling, can cause trips to some destinations to be much more widely spaced in order to have more buses for other destinations.
Bus On Demand was referred to by at least one source as a means of reducing exhaust pollution by reducing bus mileage. If this is a goal, then I am suspicious that Bus On Demand would worsen the quality of service by making the target pickup for the first person to arrive at a bus stop 20-25 minutes instead of 1 to 25 minutes' wait depending on when the last bus departed on a fixed schedule.
Other things that Bus On Demand was supposed to do but manual scheduling could also do, is rectangle routes such as MK long full to All Star short leg empty to MGM long full to Polynesian short empty to MK instead of separate routes MK to All Star and MGM to Poly with the buses running empty one way.
More Disney Hints:
http://members.aol.com/ajaynejr/disney.htm
Did you know that all of Disney World and the town of Celebration is an epcot?
Did you know that the E in Epcot stands for "experimental"?